Kindling is a widely used model for the development of seizures and epilepsy in which the duration and behavioral involvement of induced seizures increases after seizures are induced repeatedly.[1] It is used by scientists to study the effects of repeated seizures on the brain.[1] A seizure may increase the likelihood that more seizures will occur; an old saying in epilepsy research is "seizures beget seizures".[1] Repeated stimulation "lowers the threshold" for more seizures to occur.[2] In the kindling model, seizures begin to occur spontaneously after repeated subconvulsive stimuli.[3]

The brains of experimental animals are repeatedly stimulated, usually with electricity, to induce the seizures.[1] Chemicals may also be used to induce seizures.[4] The seizure that occurs after the first such electrical stimulation lasts a short time and is accompanied by a small amount of behavioral effects compared with seizures that result from repeated stimulations.[1] With further seizures, the accompanying behavior intensifies, for example progressing from freezing in early stimulations to convulsions in later ones.[5] The lengthening of duration and intensification of behavioral accompaniment eventually reaches a plateau after repeated stimulation.[1] Even if animals are left unstimulated for as long as 12 weeks, the effect remains; the response to stimulation remains higher than it had been before.[4]

It has been reported that repeated seizure stimulation can result in spontaneous seizures, but studies have had conflicting findings on this question.[1] In humans, some seizure disorders come to an end by themselves even after large numbers of seizures.[1] However, in both human epilepsy and in some animal models, evidence suggests that a process like that found in kindling does occur.[1]

The kindling model was first proposed in the late 1960s by Goddard and colleagues.[6] Although kindling is widely a widely used model, its applicability to human epilepsy is controversial.[1]

The word kindling is a metaphor: the increase in response to small stimuli is similar to the way small burning twigs can produce a large fire.[4]